Electron scattering induces a polarization in the cosmic microwave background (CMB) signal measured in the direction of a galaxy cluster due to the presence of a quadrupole component in the CMB temperature distribution. Measuring the polarization towards distant clusters provides the unique opportunity to observe the evolution of the CMB quadrupole at moderate redshifts, z~0.5-3. We demonstrate that for the local cluster population the polarization degree will depend on the cluster celestial...

Source: http://arxiv.org/abs/astro-ph/9903287v1

The frequency distribution of photons in frequency that results from single Compton scattering of monochromatic radiation on thermal electrons is derived in the mildly relativistic limit. Algebraic expressions are given for (1) the photon redistribution function, K(nu,Omega -> nu',Omega'), and (2) the spectrum produced in the case of isotropic incident radiation, P(nu -> nu'). The former is a good approximation for electron temperatures kT_e < 25 keV and photon energies hnu < 50...

Source: http://arxiv.org/abs/astro-ph/9910280v3

It has been recently realized (Rephaeli 1995) that the relativistic corrections to the spectral distortions of the cosmic microwave background (CMB) measured in the direction of clusters of galaxies containing hot gas are significant and should be detectable with the forthcoming experiments. In the present paper we calculate the correction terms that are proportional to $V_{r}/c\times kT_e/m_ec^2$ and $(V/c)^2$ to the standard formulae describing the spectral distortions caused by the bulk...

Source: http://arxiv.org/abs/astro-ph/9804125v2